The present invention relates to flooring systems. More particularly, the present invention relates to hardwood flooring systems which resist damage from moisture, thereby manifesting improved performance and longevity.
Hardwood floors have enjoyed widespread acceptance and use in modern times. Such floors are commonly found in quality houses, auditorium stages, ballrooms, and such floors are essentially utilized for sports arenas for such games as basketball, volleyball, hand ball and squash, where the resilience of the hardwood playing surface is an essential element of the sports activity.
Hardwood floors are usually formed of strips or parquet squares of hardwood which have been precisely milled, so that when the strips or squares are laid down in a desired arrangement, they self-lock together to provide the desired smooth hardwood surface.
One commonly employed locking mechanism has been tongue and groove joinery wherein the hardwood strips and squares have been precisely milled so that opposite sidewalls define tongues and mating grooves.
One of the most devastating hazards facing hardwood floors is damage resulting from moisture. While this problem has been known for many years, little progress has been heretofore realized in achieving a workable solution. Techniques such as use of moisture-resistant impregnation materials, protective coatings, air-flow passages under the floor, vapor barriers, drain channels and the like have become standard practice, with little positive improvement against catastrophic and irreversible damage attributable directly to excessive moisture absorption by the floor.
Wood floors absorb moisture. Such moisture may be the result of surface flooding, or it may be due to condensation in areas of high humidity. Hardwoods absorb water vapor in areas of high humidity, leading directly to buildup of excessive moisture content. Applicant, who has worked in the field of hardwood flooring systems for many years, has discovered that most moisture damage may be attributed to moisture penetration along the unprotected sidewalls of the slats or squares. While varnish coatings protect the top surface, and sleepers elevate the bottom surface, nothing effectively prevents moisture from entering the wood along the sidewalls.
As hardwood absorbs moisture, it expands in volume. Since the hardwood slats and squares tightly abut each other along the side dimensions, the only dimension having freedom of movement is vertical, and the wood tends to buckle to form cups and crowns. Unfortunately, because the floor is so tightly and rigidly constrained in dimensions parallel to the plane of the surface, when the hardwoods expand up or down, the internal fiber structure is destroyed, and the buckling and warpage remain, even after the excessive moisture has been driven out of the wood.
Representative patents illustrative of the prior art approaches and systems which were considered in preparation of this patent include U.S. Pat. Nos. 4,449,342 to Abendroth, 3,713,264 to Morgan, Jr., 3,518,800 to Tank, 2,952,938 to Abrams, 2,862,255 to Nelson, 1,407,679 to Ruthrauff, 1,275,476 to Roy, Re. 26,239 to Rockabrtand et al, and French Pat. No. 417,105.